Cell type specificity of neurovascular coupling in cerebral cortex

Area of Science:

• Neuroscience
• Cerebrovascular Physiology
• Neuroimaging

Background:

• Understanding the link between neuronal activity and cerebral blood flow is crucial for interpreting functional Magnetic Resonance Imaging (fMRI) signals.
• Identifying the specific cellular and molecular mechanisms governing cerebrovascular regulation is a key challenge in neuroscience.

Purpose of the Study:

• To elucidate the cellular and molecular mediators of neuronal activity-induced cerebrovascular responses.
• To determine the role of specific neuronal populations in driving cerebral hemodynamics.
• To investigate the implications for Blood Oxygenation Level Dependent (BOLD) fMRI signal interpretation.

Main Methods:

• Utilized optogenetic stimulation in mice to selectively activate cortical excitatory and inhibitory neurons.
• Employed 2-photon imaging to observe real-time vascular responses.
• Investigated the involvement of Neuropeptide Y (NPY) and its Y1 receptors in vasoconstriction.

Main Results:

• Selective activation of cortical excitation and inhibition produced distinct vascular responses.
• Identified Neuropeptide Y (NPY) acting on Y1 receptors as the primary vasoconstrictive mechanism.
• Suggests that NPY-positive inhibitory neurons may significantly contribute to negative BOLD fMRI signals.

Conclusions:

• The NPY-Y1 pathway is a critical regulator of cerebral hemodynamics.
• Task-related negative BOLD signals in the cortex may be largely mediated by NPY-expressing inhibitory neurons.
• The NPY-Y1 pathway presents a potential therapeutic target for cerebrovascular diseases.